Studies on Hepatic Sulfobromophthalein Removal During Infusion

Experiments were performed with the infusion of sulfobromophthalein (BSP) for brief periods (15 mm.) in man, following an initial massive dose of dye at the beginning of the experiment. Infusion was such as to ensure a continuous increase in the plasma BSP level. In these conditions, BSP removal due to the storage capacity of the liver was studied. The rate of removal was found to depend on the concentration gradients of BSP/protein in the serum and in the liver cell. It was also shown that the values for the hepatic removal determined according to this method are correlated in a highly significant manner with the values for the BSP clearance. L WEB FUNCTION TESTS with intravenously administered sulfobromo-phthalein (BSP) are based on the rate of removal of this substance from the blood. Various factors, affecting the liver cell in different manners, are involved both in the classic BSP retention test and in the BSP clearance test. These are: the hepatic blood flow, which car-ries the BSP to the liver, and the capacity of the liver cell to remove and store, and to excrete BSP, by which latter mechanism it is re-leased into the biiary canaliculi. The significance of the hepatic blood flow will easily be appre-ciated, and its value has been demonstrated experimentally (1, 4, 5). The capacity of the liver cell to absorb BSP has also been analyzed in numerous experiments (1, 7), and has been found to depend on the concentration of the dye in the surrounding medium and to be related to purely chemicophysical factors, being limited only by the protein content of the liver cell (1). On the contrary, excretion of BSP by the liver corresponds to a true functional activity, upon which the metabolism and excretion of the dye are dependent (8, 11)